Electrical socket and receptacle.



L. KELLNBR.

ELECTRICAL SOCKET AND REGEPTAGLE.

APPLICATION FILED MAY 13, 1913.

1,091,226 Patented Mar. 24, 1914.

UNITED STATES PATENT OFFICE.

ncurs xnnnnna, or new "coax, it. a

ELECTRICAL SOCKET AND QEOEI'TACLE.

Specification o! Ietters latent.

'Patented'Man-M, 1914.

Application fled Icy 18, 1913. Serial 1T0. 767,258,-

tain new and useful Improvements in. Electrical Sockets and Receptacles,of which the following is a full, clear, and exact description.

This invention relates to means for preventing the unauthorized removalof electric lamps, fuse plugs and similar devlces from their sockets orreceptacles and has special reference to that class of lamps, plugs,etc., which engagewith their sockets or receptacles by means of a screwthread. The ordinary Edison lamp is provided with a threaded metallicbase which engages with a threaded metallic shell in the socket orreceptacle to hold the lamp in place and various other devices in the,electrical art are similarly equipped with these threaded bases for thepurpose of mounting and securing them in the sockets or receptacles withwhich they coiiperate when in use, and my invention extends to all suchdevices. The theft of lamps and other devicesof the kind re ferred to,is quite common and the losses in many instances are severe, merelybecause the devices can be removed by anyone from the socket by simply.unscrewing them.

My invention provides a construction which permits the lamp or otherdev1ce to be screwed into its socket-in the ordinary way,bu't when anattempt is made to unscrew the lamp, the threaded shell with which thelamp engages, rotates and thus prevents relative rotation of the lampandshell which thereby defeats its unauthorized removal. To remove thelamp, it becomes necessary to insert a key into the socket or receptaclewhich, when properly manipulated, actuates a detent which prevents therotation of the threaded shell when the lamp is turned in' a directionto unscrew and remove it. Thus anyone provided with a key is able toremove the lamp while all others are prevented from so doing.

The details of my invention. will be described in connection with theaccompanying drawing in which;

Figurel, isa side elevation of an ordinary incandescent lamp and" lampsocket showing the key-hole therein; Fig. 2, is a vertical transversesection of the sfocket; Fig. 3, is a section of the socket taken on linesimilar manner.

to the view shown in Fig. 2; Fig. 4, is a plan of the upper face of theinsulating base of the socket; Fig. 5, is a plan of the lower face ofsaid base; Fig. 6, 1s a plan of the ring which sustains the threadedshell, a portion being broken away; Fig. '7, is a plan of the bottom ofthe threaded shell; and Fig. 8, is an enlarged detail takenon the liney-g of Fig. 6 and extending'through a portion of the insulating base.

-w-m of Fig. l,,thesame being at right angles The lamp socketillustrated is of a usual 7.

construction and comprises the outer casing 1 and the insulatin base 2,the latter being slotted and provi ed with p'assages variously locatedfor the metallic parts and the screws which hold them in place by whichthe current is carried to the two terminals. As here shown, the socketis provided with a key 3 for turning the current on and off, but theinvention is applicable to a keyless socket as well as to various otherforms of sockets and receptacles. The conductors leading to the socketare indicated by 4;, and 5. one of them being attached to the bracket 6,by means of a suitable binding screw and the other to the bracket 7 in aThe bracket 7 is in one piece with ametallic yoke 8, in which the keyshaft 3 is mounted. This shaft carries into contact with the threadedshell to be hereinafter referred to, while the other bracketv 6 connectswith a' center contact 9, also referred to hereinafter.

An important portion of my invention relates to the construction andmounting of the threaded shell in which the lamp neck is to be screwedand from whichitis, to be unscrewed. This shell is indicated by .10 andingi 1 opposite its open end. The bottom of this shell is a disk llhaving a circular opening in the center through which'the' center'contact' 9 passes and from which it is insulated" by a disk of mica 9'.This disk or bottom is covered on its .outer face by a ring '12 ofsubstantially the same diameter, which ring has a cylindrical neck, 13',passing through the opening in the disk and being eyeleted to a secondring 14, wl'1ich rests a cross head 9 of metal which may be thrownoccupies the usual position inside of the casagainst the inner face'ofthe bottom of the V shell. Thus, the bottom of the shell is con-.

fined between the outer andinner rings 12 and 14; and the constructionis such that the shell can be rotated independently of both of the ringsbetween which it is held. The -.ring 12 is secured to the lower face ofthe insulating base 2 by means of two screws 15 and 16, which passvertically downward through the base and project beyond its lower faceto engage the ring. In this manner the ring is anchored and preventedfrom rotating in either direction. The ring is provided with a series ofsubstantially recta-ngular openings 17, there being six of these shown,but more or fewer may be used if desired.

The bottom 11, of the threaded shell is provided with a series of springtongues 18 formed integrally therewith. All of the tial direction andhaving a bias toward the ring 12. Thus, the threadeii shell can berotated in one direction through only a very short angle before thetongues 18 drop into the openings 17 in the ring 12 and strike againstone of the radial walls of the latter which thereby prevent the furtherrotation Y I of the shell. In forming the. tongues 18 in thbottom of thethreaded shell, portions of the material of the bottom in front of eachtongue are removed to form openings 19, for a purpose which willhereinafter appear. The base 2, is provided with a vertical chamber 20of rectangular cross section in which is located a bolt 21. The upper orrear end of this bolt is beveled as shown in Fig. 3, and is preferablymade of insulating material, while the lower or frontend is also beveledor formed with a point 22 and occupies a position directly opposite oneof the bolts 17, in the ring 12. The bolt is normally held in its upperor withdrawn position regardless of the position of the socket, by meansof a spring 23. The upper .end of the bolt' chamber 20 communicates witha key-way 24, leading transversely through the casing 1 and theinsulating base 2. A key 25 which is adapted to enter this key-way,consists of a tubular shaft having a longitudinal slot along oneside anda beveled end and the key-way is correspondinglyshaped so that a crosssection thereof is somewhat of the shape of a horseshoe or the letter U,this being done to prevent the regular key from being replaced byordinary devices such as a nail or wire.

. The beveled'end of the key when thrust through the key-way engages theupper beveled end of the bolt 21 and forces itdownward so that its point22 will not only pass through the opening in ring 17, but-will alsoenter a space 19 in front of one of the tongues in the bot-tom of thethreaded shell and engage the radial wall of said space to prevent therotation of the threaded shell in the direct-ion in which said shell ispermittedto rotate by the tongues 18.

The-operation is as follows: The direction :of the tongues 18 is suchthat they will engage with the openings 17 in the ring 12 when thethreaded shell is turned in a clockwise direction which is the usualdirection for screwing the lamp into the socket. Thus, when the base ofthe lamp is presented to the threaded shell and turned in a direction toscrew inward, the shell at once becomes locked and stationary, andpermits the lamp to traverse its threads until the-center contact of thelamp is firmly in position against the contact 9 at the bottom of theshell. This is the normal working position of the lamp and it will beseen that the operation of adjusting the lamp to this position isexactly the same as that ordinarily used, nothing different beingentailed because of the application of my invention to the socket.

f now an unauthorized person who is not possessed of a key 25, attemptsto remove the lamp by unscrewing it, the frictional engagement betweenthe lamp and the threaded shell will tend to rotate the latter and sincethe tongues 18 are all pointed in the same direction, they will slipover the radial walls of the openings 17, and the shell will rotatefreely with the lamp, so that the latter cannot be unscrewed and removedtherefrom. In this Way the theft of the lamp is prevented. An authorizedperson who will be provided with a key 25, may, however, readily removethe lamp by first inserting said key into the key-way 24 and forcing itagainst the beveled end of the bolt 21; this forces the point of thebolt. into one of the spaces 19 in the bottom of the threaded shell andthereby prevents the shell from rotating backward or counterclockwisewhen the lamp is unscrewed.

Having described my invention, I claim:

1. In a device of the character described, the combination of aninsulating base, a plate fixed to said base and provided with at leastone opening therein, a threaded shell rotatable and provided with atleast one tongue adapted to pro ect into said opening and a bolt locatedin line with said opening and adapted to project through the same andengage with said shell.

2. In a device of the character described, the combination of a threadedshell having a bottom provided with a central opening, two stationaryrings between which the bottom of'the shell is confined and adapted toturn, means for automatically locking the shell against rotation in onedirection and means for manually locking the shell against rotation inthe opposite direction.

3. In a device of the character described, the combination of a rotarythreaded. shell, a fixed bearing surface against which said shellrotates, a pawl and ratchet engagement between the shell and surface toprevent rotation of the shell in one direction and a key operated boltfor locking the shell against rotation in the otherdirection.

IIO

4. In a device of the character described, In witness whereof, Isubscribe my signathe camtiinatioln of 1'(')t(a1ry1 threaded shell,ture, in the presence of two witnesses. a fixe p ate, t 1e she 1 an atehavin corresponding openings, a bolt arrangeg and LOUIS KELLNER' 5movable parallel to the axis of the shell and VVit-nesses:

fitting said corresponding" openings, and. a VVALDO M. OI-IAPIN, keycoiiperating with said bolt. REUBEN LADER.

